Spool-free fiber optic cable configuration for cable installation onto a powerline conductor

ABSTRACT

A method may include (1) coating a segment of fiber optic cable with an adhesive substance, (2) forming a coil of the segment of fiber optic cable, (3) deforming the coil into a noncircular shape defining a slot external to the coil while obeying a minimum bend radius requirement for the segment of fiber optic cable, and (4) activating the adhesive substance to stabilize the noncircular shape of the coil. Various other methods and apparatuses, such as those for performing the deforming operation, are also disclosed.

CROSS REFERENCE TO RELATED APPLICATION

This application is a divisional of U.S. Non-Provisional patentapplication Ser. No. 16/867,313, filed 5 May 2020, which claims thebenefit of U.S. Provisional Application No. 62/846,119, filed 10 May2019, and U.S. Provisional Application No. 62/941,615, filed 27 Nov.2019, the disclosure of each of which is incorporated, in its entirety,by this reference.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings illustrate a number of exemplary embodimentsand are a part of the specification. Together with the followingdescription, these drawings demonstrate and explain various principlesof the present disclosure.

The accompanying drawings illustrate a number of exemplary embodimentsand are a part of the specification. Together with the followingdescription, these drawings demonstrate and explain various principlesof the present disclosure.

FIG. 1 is a graphical representation of an exemplary operatingenvironment including a powerline conductor, to which various exemplaryembodiments may be applied.

FIG. 2 is a perspective partial view of an exemplary payload subsystememployable in a robotic system for installing a fiber optic cable abouta powerline conductor.

FIG. 3 is an end view of an exemplary cable bundle transformation forshaping or transforming a preliminary bundle of spool-free fiber opticcable into a deployable bundle for installation about a powerlineconductor.

FIG. 4 is a flow diagram of a method of manufacturing a deployablebundle of fiber optic cable.

FIG. 5 includes perspective views of a pre-twisting apparatus for asegment of fiber optic cable.

FIG. 6 is a perspective view of a wax application apparatus for asegment of fiber optic cable.

FIG. 7 is a perspective view of another wax application apparatus for asegment of fiber optic cable.

FIGS. 8 and 9 are perspective and top views, respectively, of anexemplary deforming apparatus that deforms a preliminary bundle of fiberoptic cable into a deployable bundle of fiber optic cable.

Throughout the drawings, identical reference characters and descriptionsindicate similar, but not necessarily identical, elements. While theexemplary embodiments described herein are susceptible to variousmodifications and alternative forms, specific embodiments have beenshown by way of example in the drawings and will be described in detailherein. However, the exemplary embodiments described herein are notintended to be limited to the particular forms disclosed. Rather, thepresent disclosure covers all modifications, equivalents, andalternatives falling within the scope of the appended claims.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Robotic devices may be employed to install fiber optic cable ontopreexisting power infrastructure, such as powerline conductors forelectrical power transmission and distribution lines, by way ofhelically wrapping the fiber optic cable about the powerline conductor.Such an installation may benefit from the use of the preexistingright-of-way and corresponding infrastructure (e.g., power conductors,electrical towers or poles, and so on) associated with the electricalpower distribution system. Such a robotic device may include, in someexamples, a drive subsystem that causes the robotic device to travelalong the powerline conductor (e.g., between towers or poles) while arotation subsystem of the device helically wraps the fiber optic cableabout the conductor.

Traditionally, the robotic device carries the fiber optic cable on aspool from which the cable is paid out as the cable is wrapped about thepowerline conductor. Further, to facilitate the wrapping, the spool istypically mounted on a mechanical arm that rotates about the powerlineconductor. Moreover, a counterweight is sometimes employed to balancethe weight of the spool, thus contributing to the overall weight of therobotic system.

The present disclosure is generally directed to systems and methods forproviding a “spool-free” fiber optic cable configuration or bundle forinstallation of the fiber optic cable on a powerline conductor. As willbe explained in greater detail below, embodiments of the presentdisclosure may facilitate a deployable bundle of fiber optic cable thatis of lower mass and that may be positioned closer to the powerlineconductor to promote robotic system mechanical stability compared tomore traditional fiber optic cable installation systems.

Features from any of the embodiments described herein may be used incombination with one another in accordance with the general principlesdescribed herein. These and other embodiments, features, and advantageswill be more fully understood upon reading the following detaileddescription in conjunction with the accompanying drawings.

The following will provide, with reference to FIGS. 1-9, detaileddescriptions of apparatuses and methods for providing a spool-free fiberoptic cable configuration for cable installation on a powerlineconductor. A brief description of an exemplary operating environment inwhich a robotic system for installing fiber optic cable may be employedis provided in connection with FIG. 1. An exemplary payload subsystemthat may be used with such a robotic system is discussed in associatedwith FIG. 2. An exemplary spool-free fiber optic cable bundletransformation for shaping a preliminary bundle of fiber optic cableinto a deployable bundle for installation on a powerline conductor isdescribed in conjunction with FIG. 3, and a method of providing such adeployable bundle is discussed in connection with FIG. 4. In associationwith FIGS. 5-9, various apparatuses and operations involved in providinga spool-free cable configuration are described.

FIG. 1 is a graphical representation of an exemplary operatingenvironment 100 in which various embodiments disclosed herein may beutilized. As depicted in the example of FIG. 1, operating environment100 may include an electrical power transmission or distribution systemhaving a plurality of utility poles 102 carrying multiple powerlineconductors 101. Examples of powerline conductors 101 may includestranded cables, but powerline conductors 101 are not restricted to suchembodiments. While any number of powerline conductors 101 may be carriedvia utility poles 102, two powerline conductors 101 are illustrated inFIG. 1 for visual simplicity. In some examples, powerline conductors 101are mechanically coupled to utility poles 102 via insulators 104,although other types of components (e.g., taps, standoffs, etc.) may beemployed in various embodiments. While specific reference is made hereinto utility poles 102, any type of utility pole, H-frame, lattice tower,or other type of pole or tower that carries or supports one or morepowerline conductors 101 may be included and covered in variousembodiments of operating environment 100 discussed below. Additionally,powerline conductors 101 may include one or more phase conductors,ground wires, static wires, or other conductors supported by utilitypoles 102, towers, or the like.

Also shown in FIG. 1 is a fiber optic cable 112 aligned with, andmechanically coupled to, powerline conductor 101. In some embodiments,fiber optic cable 112 may be helically wrapped about powerline conductor101, such as by way of a human-powered or electrically powered roboticdevice. However, other physical relationships between powerlineconductor 101 and fiber optic cable 112 are also possible. While onlyone fiber optic cable 112 is depicted in FIG. 1, multiple powerlineconductors 101 employing the same utility poles 102 may each have acorresponding fiber optic cable 112 attached or otherwise coupledthereto. As depicted in FIG. 1, fiber optic cable 112 may be secured topowerline conductor 101 via one or more cable clamps 106. In someexamples, fiber optic cable 112 may follow a powerline conductor 101associated with a particular phase of the power being transmitted, orfiber optic cable 112 may alternate between two or three differentphases. Moreover, each fiber optic cable 112 may carry one or moreoptical fibers for facilitating communication within operatingenvironment 100.

Additionally, FIG. 1 illustrates an optical fiber splice case 108 that,in some embodiments, splices together corresponding ends of opticalfibers of fiber optic cable 112. For example, relatively long stretches(e.g., multiple-kilometer spans) of fiber optic cable 112 that may becoupled to powerline conductor 101 may be mechanically coupled together,thermally fused together, or otherwise coupled in optical fiber splicecase 108, which may include optical couplers, amplifiers, and/or othercomponents to facilitate transmission of optical data signals from onespan of fiber optic cable 112 to the next. Additionally, in someembodiments, optical fiber splice case 108 may include wireless accesspoints and other networking components (e.g., for communication withInternet of Things (IoT) devices, smart grid sensors (e.g., voltagesensors, current sensors, and the like), and user access networks).Moreover, optical fiber splice case 108 may include optical,electromagnetic, and other types of sensors to measure powerlineconditions; environmental sensors for measuring temperature, humidity,and so on; video cameras for surveillance; and the like. To power suchcomponents, optical fiber splice case 108 may also include solar cellsand/or batteries. In some examples, such as that shown in FIG. 1,optical fiber splice case 108 may be attached to, or positioned on ornear, powerline conductor 101, as opposed to being mounted on a lowerportion of utility pole 102, thus potentially eliminating the use of aphase-to-ground transition that otherwise may be coupled with eachlength of fiber optic cable 112 to provide electrical isolation frompowerline conductor 101.

FIG. 2 is a perspective partial view of an exemplary payload subsystem200 that may be configured to carry a fiber tub 202, within which asegment of fiber optic cable 112 to be installed on powerline conductor101 is stored. In some examples, payload subsystem 200, while beingcarried by a robotic system translating along powerline conductor 101,may be rotated about powerline conductor 101 to pay out fiber opticcable 112, thus helically wrapping fiber optic cable 112 about powerlineconductor 101.

More specifically, as illustrated in FIG. 2, payload subsystem 200, insome embodiments, may include tub cradle plates 208 upon which fiber tub202 may rest. In addition, pivoting retaining tubes 205 may pivot aboutcorresponding hinges and restrain fiber tub 202 by way of free ends ofpivoting retaining tubes 205 being secured using quick-release pins 207.Consequently, fiber tub 202 may be removably attached to payloadsubsystem 200, thus facilitating the loading of a segment of fiber opticcable 112 into fiber tub 202 by way of an opening that may be covered bya tub lid 203 prior to installation on payload subsystem 200. Further,tub lid 203 may include a fiber aperture 204 through which fiber opticcable 112 may be drawn during installation. In operation, the roboticsystem, of which payload subsystem 200 is a part, may travel in atranslation direction 260 along powerline conductor 101 while payloadsubsystem 200 is rotated (e.g., via a motor operating on a rotationstructure 220, which may include a ring, bearings, and/or the like)about a rotational axis 250 that may coincide with powerline conductor101. Accordingly, when an end of fiber optic cable 112 is coupled topowerline conductor 101, the rotation of payload subsystem 200 duringthe translation of the robotic system along powerline conductor 101results in the helical wrapping of fiber optic cable 112 about powerlineconductor 101. Additionally, in some examples, a tensioner assembly 230,through which fiber optic cable 112 may pass upon exiting fiber tub 202,may control an amount of tension of fiber optic cable 112 (e.g., usingone or more clutch plates or other friction-inducing mechanisms) asfiber optic cable 112 is wrapped about powerline conductor 101.

As shown, fiber tub 202 may be shaped to define a slot 206 that may atleast partially surrounding powerline conductor 101 when fiber tub 202is installed on payload subsystem 200, thus possibly resulting in acenter of mass of the segment of fiber optic cable 112 in fiber tub 202remaining close to powerline conductor 101 relative to a strictlycylindrical tub. More specifically, in some examples, fiber tub 202 mayrevolve or orbit about powerline conductor 101, and further may rotateonce per revolution about powerline conductor 101, as may result fromthe illustration of FIG. 2. Accordingly, the center of mass of payloadsubsystem 200, including fiber optic cable 112 within fiber tub 202, mayremain close to powerline conductor 101 during the installationoperation, thus facilitating mechanical balance and stability of therobotic system throughout (e.g., without the use of a counterweight orother mechanical balancing structure).

FIG. 3 is an end (or cross-sectional) view of a representation of acable bundle transformation 300 of a bundle of fiber optic cable 112prior to deployment on a robotic system used for installation onpowerline conductor 101. More specifically, a preliminary bundle 302(e.g., a circular coil) of fiber optic cable 112 may be transformed(e.g., reshaped by mechanical forces) to a deployable bundle 304 thatmay generally conform to the internal shape of fiber tub 202 forplacement therein for installation on powerline conductor 101, asdescribed above. Moreover, in some embodiments, the shaping ofpreliminary bundle 302 may result in deployable bundle 304 defining aslot 306 external to deployable bundle 304 (e.g., outside the coil offiber optic cable 112 that forms deployable bundle 304) that aligns withslot 206 of fiber tub 202, which allows fiber tub 202 and the encloseddeployable bundle 304 to possess a center of mass located near powerlineconductor 101 due to fiber tub 202 and deployable bundle 304 at leastpartially surrounding powerline conductor 101 during the helicalwrapping of fiber optic cable 112 about powerline conductor 101.Additionally, in some examples, deployable bundle 304 may be configuredsuch that deployable bundle 304, either during the shaping operation orafterward, does not violate a minimum bend radius requirement for fiberoptic cable 112, as cited by the manufacturer of fiber optic cable 112,at any location in deployable bundle 304.

In some embodiments, an “inner wind” process (e.g., a winding processthat results in the paying out of fiber optic cable 112 from an internalsurface of deployable bundle 304 nearest a central axis of deployablebundle 304) may be used for some fiber optic cables 1122 (e.g., forfiber optic cable 112 possessing a diameter of approximately one-eighthof an inch). This embodiment may use a precision wind (e.g., a cableconfiguration in which each turn of fiber optic cable 112 contacts animmediately preceding or subsequent turn) to maximize packing density.However, in other embodiments, a helix wind (e.g., a deployable bundle304 in which the turns of fiber optic cable 112 may form helixes stackedatop one another, but where each turn may not contact an immediatelypreceding or subsequent turn) may be utilized to allow for higher speedcable payout at the cost of cable packing density.

Although the embodiments described above employ a combination ofstraight sections and curved sections for the final shape of deployablebundle 304, other shapes for deployable bundle 304 may be used in otherembodiments.

FIG. 4 is a flow diagram of a method 400 of manufacturing a spool-freeconfiguration for fiber optic cable 112 (e.g., deployable bundle 304).The steps shown in FIG. 4 may be performed by any suitable apparatus,including the apparatuses described in greater detail below. In oneexample, each of the steps shown in FIG. 4 may represent an algorithmexecuted by a processor-based system, where that algorithm includesand/or is represented by multiple sub-steps, examples of which aredescribed in greater detail below.

As illustrated in FIG. 4, at step 410, the segment of fiber optic cable112 may be “pre-twisted” such that fiber optic cable 112, duringinstallation onto powerline conductor 101, does not possess undesirabletwists when helically wrapped about powerline conductor 101 that mayimpart binding or other undue stress upon fiber optic cable 112 (e.g.,by way of the pre-twist substantially canceling out twisting of fiberoptic cable 112 that may occur during the helical wrapping). At step420, an adhesive substance (e.g., wax) may be applied to the segment offiber optic cable 112 (e.g. such that the segment of fiber optic cable112 may subsequently hold its configuration (e.g., deployable bundle304) during loading into fiber tub 202, during installation of fiberoptic cable 112 onto powerline conductor 101, and so on). At step 430,the segment of fiber optic cable 112 may be wound to form a cable bundle(e.g., a substantially circular bundle). At step 440, the cable bundlemay be deformed (e.g., to form a non-circular deployable bundle 304 orconfiguration that facilitates close positioning of the bundle topowerline conductor 101 while being rotated thereabout, such as by wayof cable bundle transformation 300). At step 450, the adhesive substancemay be activated (e.g., heated) to stabilize the bundle (e.g., bondingthe bunding together so that it may retain its current configuration).

While method 400 implies a particular set of operations in a particularorder, some steps 410-450 may be combined, and the order of some steps410-450 may be altered. For example, the adhesive substance may beapplied during the creation of an inner wind cable bundle as describedherein, or the adhesive substance may be applied during cablemanufacturing before being loaded onto a manufacturer-supplied reel.Alternatively, the adhesive substance may be sprayed onto a spool as itis being wound onto a deforming fixture reel. Other variations of method400 are also possible. Moreover, as employed herein, an adhesivesubstance may be any compound or other substance that possesses at leastsome adhesive quality (e.g., to temporarily adhere portions of fiberoptic cable 112 to itself to maintain the bundle) and is not limited tosubstances typically labeled as adhesives.

FIGS. 5-9 depict various views of possible apparatuses employable inproviding a spool-free cable configuration. However, other possibleapparatuses not specifically described herein may be used in otherembodiments. For example, FIG. 5 includes perspective views of apre-twisting apparatus 500 for a segment of fiber optic cable 112. Insome embodiments, an acceptable pre-twist or pre-torsion of fiber opticcable 112 may depend on the way in which resulting deployable bundle 304will be oriented during payout of fiber optic cable 112 onto powerlineconductor 101. For the case of a helical wrapping operation, asindicated above, an acceptable pre-twist may be specific to theimplementation of the robotic system performing the installation.Moreover, if the robotic system is configured to rotate deployablebundle 304 as it orbits deployable bundle 304 around powerline conductor101, then the pre-twist may be configured to be less than a fullcancellation of the pigtail twist such that the combination of thepre-twist and rotation of deployable bundle 304 results in installedfiber optic cable 112 wrapped about powerline conductor 101 withlittle-to-no twist.

In some embodiments, the pre-twist may be performed by turning a sourcespool end-over-end as fiber optic cable 112 is fed onto a take-up spool.Alternatively, the pre-twist can be generated by way of: (1) acquiringfiber optic cable 112 from the manufacturer on a spool with a hubdiameter, spool height, and cable thickness equal to a target spool orreel thickness, diameter, and height, and (2) placing fiber optic cable112 in a “fly fixture” and paying out fiber optic cable 112 onto anintermediate spool of arbitrary size (e.g., a spool large enough tocarry the total fiber length of the segment of fiber optic cable 112).

FIG. 5 includes various perspective views of a pre-twisting apparatus500 that may serve as the fly fixture referenced above. While FIG. 5 andother illustrations presented herein depict various types ofprototype-level apparatuses for performing various operations, otherembodiments may operate in a similar manner to those apparatusesdescribed herein while being more compatible with a high-throughputproduction environment.

In some embodiments, pre-twisting apparatus 500 may include a baseplate(not visible in FIG. 5) on which a stationary rod 501 is mounted at acenter of the baseplate. A source spool 502 may be placed on thebaseplate with rod 501 passing through a center of source spool 502. Theorientation of source spool 502 may be selected based on whether aclockwise or counterclockwise pre-twist is desired. An arm 506 ofpre-twisting apparatus 500 is pivotally attached to, and extendsradially from, rod 501. In some examples, arm 506 may include a rotaryjoint 508 to allow arm 506 to rotate relative to stationary rod 501.Examples of rotary joint 508 may include, but are not limited to, atorque clutch, a magnetic clutch, a ball bearing, a speed limitingbearing, a one-way bearing, or another type of rotary joint. In oneembodiment, rotary joint 508 may include a spring-loaded pawl andratcheting joint. At or near a distal end of arm 506, a fiber guide 510may be held vertically. The ends of fiber guide 510 may be curved toallow fiber optic cable 112 to pass from the surface of source spool 502through fiber guide 510 and up above without violating the minimum bendradius of fiber optic cable 112. In one embodiment, fiber guide 510 maybe a nonstick tube selected with its inner diameter and stiffnessmatching the requirements of fiber optic cable 112. Above rod 501 ofpre-twisting apparatus 500, fiber optic cable 112 may be collectedthrough a funnel or pair of interlocking V-groove wheels (not shown inFIG. 5). Fiber optic cable 112 may be passed over a series of rollers512 in conjunction with a tensioning spool 504 that may be coupled witha magnetic brake or clutch to control the tension of fiber optic cable112 (e.g., on a portion of fiber optic cable 112 exiting and/or enteringtensioning spool 504).

The presence of an intermediate spool (not illustrated in FIG. 5) inpre-twisting apparatus 500 for accepting pre-twisted fiber optic cable112 from tensioning spool 504 may facilitate a proper orientation offiber optic cable 112 onto a final spool or reel (also not depicted inFIG. 5), as described below. For example, if fiber optic cable 112 werepaid out from source spool 502 (e.g., via tensioning spool 504) directlyto a final or target reel or spool, the outermost layer of fiber opticcable 112 residing on source spool 502 may become the innermost layer offiber optic cable 112 on the target spool or reel. As pre-twistingapparatus 500 twists fiber optic cable 112 with a pitch equal to thecircumference of fiber optic cable 112 on source spool 502, for thispre-twist to cancel the pigtail effect of the final cable bundle (e.g.,deployable bundle 304), swapping the order of the ends of fiber opticcable 112 may be desired, with the start of fiber optic cable 112becoming the end of fiber optic cable 112, and vice-versa. This swappingmay be performed by first winding fiber optic cable 112 from tensioningspool 504 onto the intermediate spool before proceeding to winding fiberoptic cable 112 onto a final reel or spool, as discussed below.

In operation, using pre-twisting apparatus 500, fiber optic cable 112may be drawn over rollers 512 and tensioning spool 504, which in turnmay cause fiber optic cable 112 to be pulled from source spool 502. Inresponse, arm 506 may swing around rod 501 while guiding fiber opticcable 112 over the flange of source spool 502. To prevent unnecessarymotion, rotary joint 508 may be used to inhibit backwards travel of arm506 or to limit the speed of the rotation of arm 506.

In using pre-twisting apparatus 502 as a fly mechanism, paying out fiberoptic cable 112 from source spool 502 without turning source spool 502pre-twists fiber optic cable 112. By setting up the spool payoutconditions in such a manner, the resulting pre-twist may be oriented inthe opposite direction from the resulting twist that may occur whenpaying fiber optic cable out from a final inner-wound deployable bundle304, thereby cancelling that twist. To enhance the effectiveness of thiscancellation, the circumference, height, and orientation of source spool502 may be matched with that of the final spool or reel (e.g., throughthe use of the intermediate spool).

FIG. 6 is a perspective view of a wax application apparatus 600 for thesegment of fiber optic cable 112. As mentioned earlier, the wax, oranother adhesive substance, may be applied during the manufacturing offiber optic cable 112 (e.g., onto a jacket of fiber optic cable 112,which may include a polyethylene, a cross-linked polyethylene, oranother material), or by means of spraying during a winding operationonto a final reel or spool instead of as an intermediate step in thisprocess, as outlined herein. In some examples, use of wax applicationapparatus 600 may cause the deposition of a thin coating of wax on thejacket of fiber optic cable 112. In some embodiments, a desired coatingthickness may be between 30 and 100 microns. Also, the wax, in someexamples, may be applied so that the wax does not bond together thelayers of fiber optic cable 112, when residing on a spool or reel, untila later stage of the process. In some examples, a wax sprayer may beemployed to atomize the wax into small particles that settle, like dust,on the surface of fiber optic cable 112 without adhering or bonding tothat surface. In other embodiments, the wax may be coated on the jacketof fiber optic cable 112 while ensuring the wax is dried or cooled fullybefore fiber optic cable 112 is wound onto a spool or reel to preventthe layers of fiber optic cable 112 from bonding together prematurely.

The following describes one method for applying wax as a coating tofiber optic cable 112 (e.g., using wax application apparatus 600).However, other ways for applying wax or another adhesive are alsopossible, as illustrated in a wax application apparatus 700 depicted inFIG. 7. In the embodiment of FIG. 6, fiber optic cable 112 may be fedfrom an originating spool (not shown in FIG. 6). The payout tension fromthe originating spool, in some examples, may be controlled by atensioning mechanism. In one embodiment, the tensioning mechanism mayinclude a magnetic hysteresis brake with adjustable tension. Theoriginating spool may be a spool carrying the output from pre-twistingapparatus 500 (e.g., an intermediate spool, as described above). In someembodiments, the originating spool and/or fiber optic cable 112 may bewarmed before being passed to wax application apparatus 600.

From the originating spool, fiber optic cable 112 may be passed over aset of idler rollers (not shown in FIG. 6) in some embodiments to changethe orientation to direct fiber optic cable 112 downward. Waxapplication apparatus 600, in some examples, may include two pairs ofrollers (e.g., a first roller pair 602 and a second roller pair 604)geared such that a central axle-mounted gear 606 turns first roller pair602 together to push fiber optic cable 112 placed therebetween downwardwhile second roller pair 604 pushes fiber optic cable 112 upward (e.g.,at a same speed as that imparted on fiber optic cable 112 by firstroller pair 602). In some examples, first roller pair 602 and secondroller pair 604 may be of the form of caterpillar pullers or have atexture to improve grip on fiber optic cable 112. Central axle-mountedgear 606 may be driven by a motor, or connected via belt, chain, orother gear to the motor, which may also drive a take-up reel (notdepicted in FIG. 6) for fiber optic cable 112 after application of theadhesive. Between first roller pair 602 and second roller pair 604,fiber optic cable 112 may form a consistent U-shape based on firstroller pair 602 and second roller pair 604 being geared together suchthat an equal amount of fiber optic cable 112 is fed downward by firstroller pair 602 as is also pulled upward by second roller pair 604. Insome examples, at least a portion of the U-shape of fiber optic cable112 may be immersed in a wax bath 608. Other methods of immersing fiberoptic cable 112 in wax bath 608 or similar apparatus may be employed inother examples, such as placing a submerged roller 702 in wax bath 608(e.g., as shown in wax application apparatus 700 of FIG. 7), under whichfiber optic cable 112 passes with a caterpillar puller or geared rollerpushing and/or pulling fiber optic cable 112 on either side of submergedroller 702 to hold fiber optic cable 112 in tension, thus providingenhanced control of fiber optic cable 112 as it passes through wax bath608 and/or other components.

In some embodiments, wax bath 608 may be a heated bath of molten wax orsimilar material. Further, wax application apparatus 600 may include asqueegee or other wax-reducing component (not shown in FIG. 6). Themolten bath of wax may be set to a temperature that produces a desiredviscosity of the wax while preventing fiber optic cable 112 from beingsubjected to a temperature that may adversely affect the operation offiber optic cable 112. In some examples, the wax may be paraffin oranother formula tuned to improve adhesion to the jacket of fiber opticcable 112 while maintaining a relatively low melting temperature. Also,in some embodiments, the wax may be paraffin blended with vinyl acetate.Further, the wax and vinyl acetate blend may be further mixed with anadhesive (e.g., an environmentally triggered adhesive, such as alow-energy ultraviolet-activated adhesive, a water-activated adhesive,or the like), or the adhesive may be applied to fiber optic cable 112prior to applying the wax or wax/vinyl acetate blend. Consequently, insome examples, as the segment of fiber optic cable 112 is installed bythe robotic system onto powerline conductor 101, the adhesive may bepassively activated by the environment, or more actively (e.g., by wayof an ultraviolet lamp carried on the robotic system). Consequently, inthe event fiber optic cable 112 is severed after being installed onpowerline conductor 101, the adhesive may prevent fiber optic cable 112from becoming unraveled from powerline conductor 101 and creating ahazard.

Wax bath 608 may include a lid 610 with two openings or apertures, onefor fiber optic cable 112 to enter wax bath 608, and another for fiberoptic cable 112 to exit. In some examples, the exit aperture may be usedto support the squeegee to wipe away excess wax on fiber optic cable112. The squeegee may be made of rubber, felt, or other such material.In the case of rubber, the squeegee may be of the form of a rubber sheet704 (as depicted in wax application apparatus 700 of FIG. 7) with anappropriately selected hole (e.g., based on a diameter of fiber opticcable 112). After exiting the squeegee, fiber optic cable 112 may thenbe passed through an air knife 612 or other mechanism to cool the wax onfiber optic cable 112. When employing air knife 612, a vortex chillermay be used to further cool the air before blowing the air onto fiberoptic cable 112. Air knife 612 may be enclosed within a tube 706 (asillustrated in wax application apparatus 700) in some examples tofurther concentrate the cooling air around fiber optic cable 112. Afterbeing cooled, fiber optic cable 112 may be passed through second rollerpair 604, which may pull fiber optic cable 112 upward and onto a secondset of idler rollers (not shown in FIG. 6), which may guide fiber opticcable 112 onto the take-up reel.

FIGS. 8 and 9 are perspective and top views, respectively, of adeforming apparatus 800 for configuring a segment of fiber optic cable112 for deployment in a robotic system for installation on a powerlineconductor 101, as described above. As indicated above, fiber optic cable112, after exiting the wax application process described above, may bewound onto a take-up reel. In some embodiments, the take-up reel may becable reel 801 of FIGS. 8 and 9 that may be specifically designed toenable deformation of the bundle of fiber optic cable 112 via deformingapparatus 800. However, other shapes and structures for cable reel 801and deforming apparatus 800 not specifically discussed herein may beused in other embodiments.

Cable reel 801 may include three sections: an upper flange 802, a hubsection (largely obscured in FIG. 8 by the segment of fiber optic cable112 wound thereon), and a lower flange 804. Upper flange 802 and/orlower flange 804 may include a plurality of holes and/or features thatmay interact with other features of deforming apparatus 800 to holdcable reel 801 in place when fiber optic cable 112 is being deformed.

In some embodiments, the hub section of cable reel 801 may include anumber of separate components. The hub section, by way of two top arcsor sections 806 and two bottom arcs or section 808 extending from upperflange 802 to lower flange 804, may provide a round circular surfaceupon which fiber optic cable 112 may be wound onto cable reel 801. Inother examples, greater or fewer numbers of top arcs 806 and/or bottomarcs 808 may form at least a part of the hub section. After fiber opticcable 112 is wound onto cable reel 801, portions of hub section may beremoved so that fiber optic cable 112 may be deformed, possibly whileholding stationary particular sections of fiber optic cable 112 that arenot to be deformed. In the particular example of FIGS. 8 and 9, a smallportion of fiber optic cable 112 (e.g., at the top of cable reel 801near curved surface 816, as illustrated in FIGS. 8 and 9) may remainsubstantially stationary. Additionally, in some embodiments, the hubsection may include stationary portions or sections (not depicted inFIGS. 8 and 9) that may be shaped such that, in the absence of top arcs806 and bottom arcs 808, provide a noncircular surface that may form aninner surface over which fiber optic cable 112 is deformed. In someexamples, top arcs 806 and bottom arcs 808 may be removed from cablereel 801 after cable reel 801 is locked into the remainder of deformingapparatus 800 prior to the deforming operation.

Deforming apparatus 800, as illustrated in FIGS. 8 and 9, may include abaseplate 812 on which may be slidably attached a top ram 814 forshaping a top portion of the bundle of fiber optic cable 112 and abottom ram 818 for shaping a bottom portion of the bundle. Morespecifically, top ram 814 may provide a curved surface 816 (e.g., apartially curved surface with symmetrical straight side regions) that isforced against the top (peripheral) portion of the bundle, and bottomram 818 may present a protrusion 820 that is forced against the bottom(peripheral) portion of the bundle (e.g., to reshape preliminary bundle302 to produce deployable bundle 304 defining slot 306, as discussedabove in connection with FIG. 3.) In the example of FIGS. 8 and 9,threaded rods 830 may be coupled to top ram 814 and bottom ram 818 suchthat rotation of threaded rods 830 (e.g., by way of attached gears 832driven by one or more electric motors not depicted in FIGS. 8 and 9) maycause both top ram 814 and bottom ram 818 to be forced against thebundle of fiber optic cable 112 wound on cable reel 801 to reshape thebundle in the absence of top arcs 806 and bottom arcs 808. In someexamples, deforming apparatus 800 may be configured to reshape oneportion of the bundle using one ram (e.g., the top portion using top ram814) before reshaping the remaining portion (e.g., the bottom portionusing bottom ram 818). In other examples, deforming apparatus 800 may beconfigured to engage fiber optic cable 112 concurrently with both topram 814 and bottom ram 818. As a result of the deforming operation, insome embodiments, the shape of portions of deployable bundle 304 maymatch the shape of protrusion 820 and curved surface 816.

As depicted in FIGS. 8 and 9, a width of each of top ram 814 and bottomram 818 may substantially match a width of the hub section of cable reel801 between upper flange 802 and lower flange 804 such that top ram 814and bottom ram 818 may slide between upper flange 802 and lower flange804 in close proximity to prevent any portion of fiber optic cable 112from entering between ram 814 or 818 and either upper flange 802 orlower flange 804. In addition, in some embodiments, top ram 814 may becoupled to an upper top guard 815 and a lower top guard 817, whilebottom ram 818 may be coupled to an upper bottom guard 819 and a lowerbottom guard 821. Each of upper top guard 815, lower top guard 817,upper bottom guard 819 and lower bottom guard 821 may include a curvedregion substantially matching a circular edge of upper flange 802 orlower flange 804 such that upper top guard 815, lower top guard 817,upper bottom guard 819, and/or lower bottom guard 821 may halt furtherprogress of top ram 814 and bottom ram 818 into the bundle of fiberoptic cable 112.

In some embodiments, various surfaces of upper flange 802, the hubsection, and lower flange 804, along with top ram 814 and bottom ram818, may be covered by a non-stick surface or be coated between uses bya mold-release agent or other substance to promote retreat of top ram814 and bottom ram 818 from fiber optic cable 112 after the deformationoperation without disturbing the newly formed shape of fiber optic cable112.

After the deformation operation described above, in some examples, theentire deforming apparatus 800, including cable reel 801 and fiber opticcable 112, may be placed in an oven. The dimensions of baseplate 812 ofdeforming apparatus 800 may be designed to allow for deforming apparatus800 to fit within the oven. In some embodiments, the oven heatingtemperature and time may be tuned based on the specific wax used suchthat the wax melts sufficiently so that it bonds the layers of fiberoptic cable 112 together while not causing an inordinate amount of thewax to drip from fiber optic cable 112 and not causing the wax to pooldownward. Lower flange 804 may include small holes to allow excess waxto drip through, thereby avoiding excessive pooling of wax at the bottomof cable reel 801. In some embodiments, a forced air oven may beemployed with a set temperature (e.g., 60 degrees C.).

After undergoing heating, deforming apparatus 800 may be removed fromthe oven and allowed to cool. Upper flange 802 may include a hole thatallows an air line to be attached to accelerate the cable coolingprocess. After the cooling phase, top ram 814 and bottom ram 818 may beretracted by turning threaded rods 830. Upper flange 802 may be removedfrom the hub section, thereby exposing fiber optic cable 112 in theconfiguration of deployable bundle 304. Lower flange 804 then may beremoved from baseplate 812 such that deployable bundle 304 can beremoved.

Prior to installation of fiber optic cable 112 about powerline conductor101, deployable bundle 304 may be placed in fiber tub 202 with a similarcurved profile. Fiber tub 202, in some embodiments, may include an innersurface texture to provide a level of grip over deployable bundle 304.Fiber tub 202 may also possess the ability for the perimeter to beincreased in size temporarily while deployable bundle 304 is loaded intofiber tub 202, thereby improving the grip on deployable bundle 304. Insome examples, the inner surface of fiber tub 202 may be coated by alayer of an adhesive substance (e.g., wax), which may be heated togently bond the inner surface with an outermost layer of deployablebundle 304.

As discussed above in conjunction with FIGS. 1-9, apparatuses andmethods described herein may result in a spool-free fiber optic cableconfiguration or bundle for use in a helical wrapping robotic systemthat may possess a center of mass close to the center of rotation ororbit of the cable bundle, which may be coincident with the center ofpowerline conductor 101. Also, in some embodiments, the resulting cablebundle may occupy a minimal radius about powerline conductor 101 andpossess a minimal overall length, all while refraining from subjectingfiber optic cable 112 to a bend radius smaller than themanufacturer-specified bend radius, and while minimizing any fiberpumping that may occur when turning fiber optic cable 112 continually ina small bend radius, as may be done in conjunction with some spoolsystems.

EXAMPLE EMBODIMENTS

Example 1: A method may include (1) coating a segment of fiber opticcable with an adhesive substance, (2) forming a coil of the segment offiber optic cable, (3) deforming the coil into a noncircular shapedefining a slot external to the coil while obeying a minimum bend radiusrequirement for the segment of fiber optic cable, and (4) activating theadhesive substance to stabilize the noncircular shape of the coil.

Example 2: The method of Example 1, where coating the segment of fiberoptic cable may be performed before forming the coil.

Example 3: The method of Example 1, where (1) the adhesive substance mayinclude paraffin and (2) activating the adhesive substance may includeheating the coil.

Example 4: The method of Example 1, where the coil may include acircular shape prior to deforming the coil.

Example 5: The method of Example 1, where the method may includepre-twisting the segment of fiber optic cable prior to forming the coil.

Example 6: The method of Example 5, where pre-twisting the segment offiber optic cable may be performed at a rate that cancels a twisting tobe applied to the segment of fiber optic cable during subsequentwrapping of the segment of fiber optic cable about a powerlineconductor.

Example 7: The method of any one of Examples 1-6, where deforming thecoil may include applying a first force to a first portion of aperimeter of the coil to form the slot.

Example 8: The method of Example 7, where the first force may be appliedusing a first ram with a surface having a shape of the slot.

Example 9: The method of Example 7, where deforming the coil may furtherinclude applying a second force to a second portion of the perimeter ofthe coil opposite the first portion.

Example 10: The method of Example 9, where the second force may beapplied using a second ram with a surface having a shape different fromthe slot.

Example 11: An apparatus may include (1) a reel including a hub sectionthat carries a coil of a segment of fiber optic cable, where the hubsection includes at least one first removable section upon which thecoil is carried, (2) a base that securely maintains the reel carryingthe coil, (3) a first ram including a protruding surface facing a firstportion of a perimeter of the coil at which the at least one firstremovable section of the hub section is positioned, and (4) a mechanismthat facilitates movement of the first ram to the first portion of theperimeter of the coil such that, when the at least one first removablesection of the hub section is absent, the coil is deformed into anoncircular shape defining a slot external to the coil while obeying aminimum bend radius requirement for the segment of fiber optic cable.

Example 12: The apparatus of Example 11, where the slot possesses ashape matching the protruding surface.

Example 13: The apparatus of either one of Example 11 or Example 12,where (1) the reel may further include a first flange and a secondflange coupled to opposing ends of the hub section and (2) theprotruding surface of the first ram may be sized to span a length of thehub section and to enter between the first flange and the second flange.

Example 14: The apparatus of Example 13, where the apparatus may furtherinclude a first guard coupled to the first ram, where the first guard ispositioned to contact at least one of the first flange or the secondflange to prevent further progress of the protruding surface of thefirst ram into the coil.

Example 15: The apparatus of Example 11, where the apparatus may furtherinclude at least one threaded rod that, when rotated, urges the firstram toward the first portion of the perimeter of the coil.

Example 16: The apparatus of either one of Example 11 or Example 12,where (1) the hub section may further include at least one secondremovable section upon which the coil is carried, (2) the apparatus mayfurther include a second ram with a surface having a shape differentfrom the slot, where the mechanism facilitates movement of the secondram to a second portion of the perimeter of the coil at which the atleast one second removable section of the hub section is positioned, and(3) the mechanism may facilitate movement of the second ram to thesecond portion of the perimeter of the coil such that, when the at leastone second removable section of the hub section is absent, the coil isfurther deformed.

Example 17: The apparatus of Example 16, where the second portion may beopposite the first portion of the perimeter of the coil.

Example 18: The apparatus of Example 16, where the shape of the surfaceof the second ram may include at least one linear portion.

Example 19: A method may include (1) wrapping a segment of fiber opticcable about a hub section of a reel to form a coil, where the hubsection includes at least one first removable section upon which thecoil is carried, where the at least one first removable sectioncorresponds to a first portion of a perimeter of the coil, (2) couplingthe reel to a base portion of a deforming apparatus, (3) removing the atleast one first removable section from the hub section of the reel, and(4) moving a first ram toward the first portion of the perimeter of thecoil such that a protruding surface of the first ram deforms the coilinto a noncircular shape defining a slot external to the coil whileobeying a minimum bend radius requirement for the segment of fiber opticcable.

Example 20: The method of Example 19, where (1) the hub section mayinclude at least one second removable section upon which the coil iscarried, (2) the at least one second removable section may correspond toa second portion of the perimeter of the coil, and (3) the method mayfurther include (a) removing the at least one second removable sectionfrom the hub section of the reel and (b) moving a second ram toward thesecond portion of the perimeter of the coil such that a surface of thesecond ram further deforms the coil while obeying the minimum bendradius requirement for the segment of fiber optic cable.

The process parameters and sequence of the steps described and/orillustrated herein are given by way of example only and can be varied asdesired. For example, while the steps illustrated and/or describedherein may be shown or discussed in a particular order, these steps donot necessarily need to be performed in the order illustrated ordiscussed. The various exemplary methods described and/or illustratedherein may also omit one or more of the steps described or illustratedherein or include additional steps in addition to those disclosed.

The preceding description has been provided to enable others skilled inthe art to best utilize various aspects of the exemplary embodimentsdisclosed herein. This exemplary description is not intended to beexhaustive or to be limited to any precise form disclosed. Manymodifications and variations are possible without departing from thespirit and scope of the present disclosure. The embodiments disclosedherein should be considered in all respects illustrative and notrestrictive. Reference should be made to the appended claims and theirequivalents in determining the scope of the present disclosure.

Unless otherwise noted, the terms “connected to” and “coupled to” (andtheir derivatives), as used in the specification and claims, are to beconstrued as permitting both direct and indirect (i.e., via otherelements or components) connection. In addition, the terms “a” or “an,”as used in the specification and claims, are to be construed as meaning“at least one of.” Finally, for ease of use, the terms “including” and“having” (and their derivatives), as used in the specification andclaims, are interchangeable with and have the same meaning as the word“comprising.”

What is claimed is:
 1. A method comprising: coating a segment of fiberoptic cable with an adhesive substance; forming a coil of the segment offiber optic cable; deforming the coil into a noncircular shape defininga slot external to the coil while obeying a minimum bend radiusrequirement for the segment of fiber optic cable; and activating theadhesive substance to stabilize the noncircular shape of the coil. 2.The method of claim 1, wherein coating the segment of fiber optic cableis performed before forming the coil.
 3. The method of claim 1, wherein:the adhesive substance comprises paraffin; and activating the adhesivesubstance comprises heating the coil.
 4. The method of claim 1, whereinthe coil comprises a circular shape prior to deforming the coil.
 5. Themethod of claim 1, further comprising pre-twisting the segment of fiberoptic cable prior to forming the coil.
 6. The method of claim 5, whereinpre-twisting the segment of fiber optic cable is performed at a ratethat cancels a twisting to be applied to the segment of fiber opticcable during subsequent wrapping of the segment of fiber optic cableabout a powerline conductor.
 7. The method of claim 1, wherein deformingthe coil comprises applying a first force to a first portion of aperimeter of the coil to form the slot.
 8. The method of claim 7,wherein the first force is applied using a first ram with a surfacehaving a shape of the slot.
 9. The method of claim 7, wherein deformingthe coil further comprises applying a second force to a second portionof the perimeter of the coil opposite the first portion.
 10. The methodof claim 9, wherein the second force is applied using a second ram witha surface having a shape different from the slot.
 11. A methodcomprising: wrapping a segment of fiber optic cable about a hub sectionof a reel to form a coil, wherein the hub section comprises at least onefirst removable section upon which the coil is carried, wherein the atleast one first removable section corresponds to a first portion of aperimeter of the coil; coupling the reel to a base portion of adeforming apparatus; removing the at least one first removable sectionfrom the hub section of the reel; and moving a first ram toward thefirst portion of the perimeter of the coil such that a protrudingsurface of the first ram deforms the coil into a noncircular shapedefining a slot external to the coil while obeying a minimum bend radiusrequirement for the segment of fiber optic cable.
 12. The method ofclaim 11, wherein: the hub section comprises at least one secondremovable section upon which the coil is carried; the at least onesecond removable section corresponds to a second portion of theperimeter of the coil; and the method further comprises: removing the atleast one second removable section from the hub section of the reel; andmoving a second ram toward the second portion of the perimeter of thecoil such that a surface of the second ram further deforms the coilwhile obeying the minimum bend radius requirement for the segment offiber optic cable.